For analog or other noise susceptible circuits, a high self gain, i.e., transconductance, over current gain (gm/Id), is beneficial, e.g., to reduce noise. However, devices comprised of silicon on insulator (SOI) materials can have lower drive currents in strong saturation applications compared to BULK devices. For example, a fully depleted SOI material at a relatively low SOI thickness intrinsically has a lower drive current in the high saturation region. In this way, SOI devices can have a relatively lower gm compared to bulk technologies in the high current regime.
In earlier attempts to address these problems, devices can have a locally increased threshold voltage (Vt) adjacent to a source region, resulting in a gm boost. As an example, devices can use a cold implant on the source side to profit from better injection on an asymmetric device. However, all of these devices suffer from lowered mobility due to the relatively high channel doping near the source region, resulting in increased mismatch and noise.